As the severe storms ripped through the States in April, they didn’t only bring the record number of tornadoes seen in one month. The storms also brought damage from giant hail and flooding rains.

The torrential rains have swelled the size of the Mississippi and Ohio Rivers, both of which are now full and threatening to breach their levees. Now, on top of this, the melted snow from further upstream is now heading down the Upper Mississippi River, bloating the waters even further.

The Mississippi and the Ohio rivers meet at Cairo, Illinois, at which point they simply become the Mississippi, as it flows south towards New Orleans. After the extra pulse of snowmelt has roared past Cairo, it is expected to bring the worst floods ever recorded along a 600-kilometre stretch of the Mississippi.

Areas along the river which are not protected by levees can expect serious flooding, and many people will have to be evacuated.

To prevent the flooding being worse than it might be, the Army Corps of Engineers blew up a levee near the town of Cairo, a levee designed to be demolished if the flooding is severe enough. This allowed some of the water to pour over the Birds Point-New Madrid Spillway, a measure which has only been necessary once before, during the historic 1937 flood.

Breaching the levee has certainly helped matters, but the demolition was not in favour of everyone, as it resulted in the flooding of 130,000 acres of rich farmland. It only took place after a series of failed court challenges, brought by the Attorney General of Missouri, which ended at the Supreme Court on Monday.

These pictures from NASA's Earth Observatory show the area where the flooding has taken place:

This first image was taken on April 29th, before the levee was destroyed.

This second image was taken on 3 May, and shows the vast area which is now underwater.

Although the demolition of this levee has alleviated the problems, there is still a lot of water gushing through these rivers. It may also be necessary to use the Bonnet Carre Spillway, just upstream from New Orleans, in order to relieve the pressure on the levees in the city.